


Expectations

by Adel Mortescryche (Mortescryche)



Series: Poisonous Smiles Wrapped in Diaphanous White (Fem!Byakuran AU) [1]
Category: Katekyou Hitman Reborn!
Genre: Absent Characters, Aged-Up Character(s), BAMF Sawada Tsunayoshi, Cis Female Byakuran, Does this count as BAMF Tsuna?, Established Relationship, F/M, Friendship, Genderbending, Genderswap, If You Squint - Freeform, No Underage Sex, Pegging, Polyamory, Porn With Plot, Post-Canon, Pre-OT3, Rule 63, Smut, Underage Character(s), fem!Byakuran, oh god what have I done
Language: English
Status: Completed
Published: 2016-09-07
Updated: 2016-09-07
Packaged: 2018-08-13 19:09:04
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,926
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7982929
Author URL: https://archiveofourown.org/users/Mortescryche/pseuds/Adel%20Mortescryche
Summary: <blockquote class="userstuff">
              <p>In which Byakuran gets Tsuna to try something that he never saw himself agreeing to try any time soon. Which is par for the course, really. And Kikyou finds ways to keep himself entertained along with Takeshi and Hayato - misery always has loved company, after all. And Tsuna has bigger problems to deal with, but those can wait. (Really, they can.)</p>
            </blockquote>





	Expectations

**Author's Note:**

> Izzy, if you get around to reading this - this is _entirely_ your fault. The other fem!Byakuran/Tsuna piece is still being written. Byakuran is being entirely too stubborn.
> 
>  **Trigger warnings at the bottom** , as usual. Read for a note on Yuni's part to play in this piece.

Tsuna felt like he was burning up inside. The white heat of unadulterated pleasure zinged up and down his spine in a loop that had him ducking his head, face almost completely pressed into the sheets beneath, forehead pillowed on his folded forearms, and he moaned unreservedly, because this was nearly more than he could fucking _take._

Breathless laughter from behind and above him, and a light kiss pressed delicately and low against the back of his neck. It set off another chain of shivers, because it wasn’t like he was already overstimulated here, right.

“My, Tsunayoshi-kun. One would think you’ve never done this before.”

The voice sounded perfectly mild and coy, and the words ended in a smile. If Tsuna hadn’t been able to hear the strain in her usually flawless laughter, he might have thought that this wasn’t doing anything for Byakuran at all. He gave a choked laugh of his own, and managed to turn his head just about enough to shoot a sharp grin at her over his shoulder.

 “That’s not too surprising, considering that I haven- _ngh.”_ His words broke off midway through, stolen away by the involuntary groan that escaped his throat.

“Considering that you _have?”_ she asked, laughing again, and ignored the invective he grunted out, instead pressing a long fingered hand between his shoulder blades, holding him down effortlessly. Still moving her hips in slow, steady thrusts and somehow managing to hit his prostrate every damned time.

Tsuna groaned, near helplessly, not fighting against her and _staying_ down, because his body was shuddering too hard for him to feel at all inclined to push himself back up. That, and it felt way too good. Something at the back of his mind said that he probably shouldn’t be enjoying this quite so much, that being pressed face first into a bed, balancing awkwardly on his knees with his legs spread wide while his… while Byakuran worked him over with a strap-on dildo sliding in and out of him should feel _demeaning,_ somehow, should make him feel weird, but. No. No. This felt too good, and anyone who tried to tell him otherwise could go and-

“ _Ah,_ ” he hissed out, and forced himself up on one elbow, nearly slipping back down, but he managed to get enough stability to work himself backwards, moving in time with the next thrust and earning himself an appreciative groan.

“And to think that you said you didn’t want to try this,” she said, the words mixed in with breathless laughter, as she got a slim arm around his waist to tug him closer.

“I was an ignorant and a blind fool- _fuck_ don’t stop. _Byakura-”_ he tilted his head to the side, breath hitching when she set her teeth against the skin of his neck, right where it merged into his shoulder. Her chest was pressed snugly against his back; he could feel the gentle swell of her breasts, the tightened nubs of her nipples dragging against his skin.

It was maddening – but not as maddening as light touch of her fingers ghosting over the flesh of his lower abdomen. So close to where he wanted them, and just _staying_ there. Holding him steady while she had her way with him. He gritted his teeth, and rocked his hips in time with hers, feeling himself shiver, feeling his arms nearly give out because it felt too damn good.

“ _Tsuna-”_ she breathed, right against his ear, and he jerked his head away. Let himself fall back onto his elbows, _feeling_ the way the sudden shift in his center of gravity made her slide deeper. And hearing her breath hitch when managed to his fingers round the back of her neck, dragging her closer so he could press their lips together.

It was a messy- absolutely sloppy, and the clash of teeth ensured that Tsuna was left with red stained lips. It didn’t stop him, though, groaning deep and low, and feeling Byakuran tremble against his back, her mouth open and wet and Tsuna could lose himself inside it. _Had_ lost himself, had lost hours trading kisses with her in the dark of his room when the rest of the household was too deep in sleep to notice the visitor that had stopped by in the middle of the night to say ‘hi’ with a devilish smile adorning her face.

When Byakuran dragged herself away from his mouth, her lips were glistening, their edges stained just as red as Tsuna’s torn lips, and her eyes glittered, watching him with a heady mix of hunger and amusement lining the cut of the smile on her face.

Tsuna stared back at her, his lips aching, his heartbeat thudding in his ears, and couldn’t find it in himself to not want every inch that she gave him.

“Get on your back,” she said, pulling away to sit on her heels. Waiting.

Tsuna craned a look over his shoulder again, took in the way she was smiling, one part sweet and three parts wild, her messy ivory hair flying just about everywhere and glinting faintly lilac in the light of the moon streaming through his window.

And he did.

*

“Lord Byakuran had me buy her a strap-on.”

Takeshi choked on the mouthful of tea he’d just taken. And distantly heard Hayato’s fingers clatter against the keyboard of his laptop.

“What the everloving _fuck._ ” Hayato demanded testily, staring at the mint-haired Funeral Wreath that was lounging in the seat opposite them, completely immersed in whatever it was that he was looking at on his phone.

Takeshi, for his part, mournfully surveyed the tea that he’d managed to spray all over the table. It hadn’t gotten anywhere near Kikyou, thankfully - he’d just tilted himself out of the way, eyes not leaving his phone screen for even a second.

“No, really. _What.”_ Hayato repeated.

“What, ‘what’? There aren’t many ways to misinterpret what I just said.” Kikyou said, bland, but Takeshi caught the darkly amused glance he shot at the two of them. Not that he could blame him; Takeshi suspected that their expressions were hilarious right about now.

“Haha. A strap-on? Really?” Takeshi asked, grinning widely, because there really wasn’t much else he could do.

It made for an… _interesting_ mental image, alright. From how red Hayato’s cheeks had gotten, he probably agreed. Even if he somehow managed to shake it off long enough to yell at Kikyou a moment later.

“’Too much’? Oh? O-ho? Don’t lie to yourself, dear, you’d have done the same if it were Sawada asking, don’t claim that you _wouldn’t_.” Kikyou murmured, smirking ever-so-slightly, in response to what Hayato had barked at him.

It made Hayato quiver, incensed, but he didn’t deny it. Takeshi snickered, just a bit, and patted him comfortingly on the shoulder.

It was a sign of just how agitated the bomber was, when he made no move to shrug Takeshi’s hand away.

“Any particular reason you’re sharing this with us? Kikyou?” he asked, tacking a cheery laugh to the end of his question when Kikyou’s gaze switched to him, brows rising.

“O-ho. No particular reason, I just thought you might like to be prepared to deal with Sawada later.”

“ _Deal_ with him? I’ll show you how to deal, you-” Hayato bit out, trailing away into coarse Italian invectives, red faced and disapproving, and Takeshi couldn’t help it. He just dissolved into laughter again, because the look Kikyou had pointed Hayato’s way was almost painfully playful. And incendiary.

He could understand why. _He_ certainly enjoyed winding Hayato up and watching him go. It was entertaining and never really got old. Not when Hayato puffed up like an offended cat. And even yowled like one, if you poked him just the right way.

He wasn’t sure what he’d been expecting, when Tsuna and Byakuran fell in with each other after they returned from the future-that-never-was, but it hadn’t been this. Not hours spent sniping back and forth with Byakuran’s Wreaths. He supposed he should call them her friends, now, but the word didn’t seem to suit them quite well.

Kikyou could actually be fun to hang out with, if he was in the mood to be interactive. He usually wasn’t, just camped out in the corner and messing about with his phone or muttering something to Zakuro in an undertone if the older man chose to come along. But the days like this, when he was in a mood to be playful, were hilarious. And all the more fun because he tended to direct a majority of his barbs Hayato’s way.

Takeshi usually just sat back with a grin, watching while Hayato shifted from pink to red to purple, close to blowing up but controlling himself because he didn’t want anyone in the house waking up while they all camped out in the Sawada household’s kitchen.

They were just lucky that this particular time had them camped out in the kitchen of the house Byakuran and Yuni had bought for their personal use in Namimori. The first time they’d stopped by, after the Representative Battles, after _everything_ , Takeshi and Hayato had traded glances, somehow finding it in themselves to not comment when they realized just how close it was to Tsuna’s house.

At least they weren’t reduced to quietly hiding in the kitchen in the middle of the night anymore, watching for assassins while Tsuna and Byakuran were otherwise occupied. Or, well. They weren’t reduced to doing that every time.

“This is going to be interesting, if Gamma gets stuck baby sitting with us, later,” Kikyou had remarked once, mild, and Takeshi had cracked up. It had been impossible not to. Hayato had smothered him with Tsuna’s mom’s oven mitts to keep the sound down.

“A _strap-on?”_ Hayato repeated, in a mutter, actually sounding thoughtful this time. And just a little worried for Tsuna.

Obviously. Takeshi could understand why, he trusted Byakuran about as much as Hayato did. But it wasn’t worth thinking about, right now. Especially not when Kikyou would be able to tell. So Takeshi rolled his eyes, and elbowed him in the side.

“Figure out your kinks on your own time, Hayato.”

“What? I _wasn-_ Yakyu- _baka!”_

There. Distraction successful.

Kikyou was smiling at him, eyes sharp. So Takeshi smiled back, with teeth, and didn’t dodge when Hayato aimed a whack at the back of his head.

*

“So. We should do that again sometime.” Tsuna said, grinning into the flesh of Byakuran’s stomach when she aimed a lazy kick at his back.

“You’d been so _suspicious,_ Tsuna-kun. As if I would hurt you. For shame.” She drawled, smiling brightly down at him when he shot her an arch look.

“Oh, sure. There’s absolutely no chance that you’d hurt me when you’ve got me down on my back and at your mercy. Absolutely no chance at all.” He shot back, drawling the words out about as sarcastically as her, and she burst into delighted peals of laughter.

“Ah, Tsunayoshi-kun. You are such a delight,” she said, smirking when he scoffed.

He let himself be drawn back up for a languid kiss, though, not complaining when she wound a leg over his hips.

“He’s asked me to stop in for another meeting,” he said, once he’d satisfied himself with licking his way into her mouth till she shivered.

Byakuran peered up at him, her gaze razor-sharp even while her lips were swollen and a pretty shade of debauched pink.

“Did he now. The old man should stop meddling, it’s well past due,” she replied, her voice low and hard. And somehow smiling in spite of that.

“Well, he’s been meddling nearly in my entire acquaintance with him. Especially the earlier ones that I remember. And he wants to make sure the line is continued. He seems to think this is the best way to make sure it’s done legitimately.”

Tsuna’s tone was wry. He distracted himself with drawing circles over Byakuran’s shoulders, just so he didn’t need to watch her eyes darken with murder and laughter in equal measure.

“You say that like he thinks you’ll stick on to whichever lamb is married away to you like an innocent little boy,” she said, smiling, and Tsuna winced. And followed the wince up with a tight smile.

“Funny. Xanxus said the same thing when I spoke to him about it, later.”

That? Earned him a pair of raised eyebrows.

He gave a little shrug, his smile broadening when it jostled the both of them.

“Hey, he was the best person to talk to. The Ninth’s _his_ dad, after all. If anyone wanted to talk about how shitty my dad is, or wanted to try and understand his decisions, they’d probably decide to come after me, too.”

“But that’s _you,_ Tsunayoshi-kun. You’re much better company,” she said, laughing when he cringed.

“I’ll deal with it when I have to. Did you speak to Yuni yet? She said she’s going to be here next week, and that she wanted to go to a water park. Since it’s summer and all.”

“Oh? That should be fun. I think I can afford to stay another week. She’s starting to get older. Old _enough_ , which can only be a good thing _._ I have these _adorable_ bikinis picked out-”

“Byakuran, stop. You’re going to give Gamma a heart attack when they get here.”

They spent the rest of the afternoon making plans and laughing, curled up in bed.

Tsuna found that he couldn’t care less, what his jii-chan wanted him to do. They probably should have asked him first, to see if he was willing to marry one of the daughters of another Famiglia to consolidate the Vongola’s power over a larger territory.

He smiled as Byakuran wrapped her arms around his shoulders, sighing into his ear while he worked his fingers into her, taking his time because he didn’t really have anywhere else to be that day. And Byakuran was finding it harder and harder to stop by as often as she had, when he’d still been in high school. Apparently being the Don of a Famiglia, even one as small as the Gesso, was more time consuming than he’d thought.

“-and she’d be so _good,_ Tsunayoshi-kun. Precognition, that could be _so_ much fun,” she was murmuring, teeth tugging at his ear lobe, and Tsuna felt his gut clench tight, heat pooling low in his belly.

“Don’t,” he muttered, mouthing at the side of her neck, and she gave a breathless laugh, tugging hard at his hair.

“You say that like you don’t like it. And like she hasn’t bloody _hinted_ at it every time we’ve met her in the last year. You lied less when I had you spread out beneath me, Tsunayoshi-kun- _ah.”_ She gasped, her hips jerking up before he used his free hand to hold her down, biting down into the meat of her shoulder when she cursed harshly.

“Later,” he said, and slid down, getting her legs over his shoulders and setting his mouth to work.

He mentally apologized to his friends for leaving them with Kikyou for longer than planned. But he really couldn’t help himself, right now. They were probably keeping themselves occupied. They’d been stuck together for long enough in the last few years, after all.

“Fucking _move,_ Tsunayoshi-kun, _”_ Byakuran ground out, her lean muscled thighs tightening like a vice on either side of his neck, and he huffed out a laugh, tugging her closer.

“Yeah,” he grunted, lips tilted in a hard little grin that would have disturbed nearly everyone who recognized him in the Main House of the Vongola. His jii-chan and dear ol’ dad included, if they ever had the misfortune of seeing it on his face.

Like hell a little mafia lamb would be anywhere near as engaging as this. Byakuran had ruined him from the moment he’d set his eyes on her, in that remote, impossible future they’d met each other in for the first time.

How they thought he’d agree to settle for anything else, for any _one_ else, was beyond him.

*

_Xanxus had looked so vindictively amused, when he’d spoken to him after that last meeting with Don Nono. Tsuna hadn’t been willing to accept he understood why. But he knew. Oh, he knew._

_As if Byakuran would agree to play second fiddle to whoever Timoteo and Iemitsu picked out for him._

_Tsuna was just relieved that she didn’t simply arrange for the deaths of all the pretty little girls Timoteo had selected from the various Famiglia that would serve as good connections for the Vongola. Maybe Byakuran had learnt a little self-restraint, in the past few years._

_(The right answer, he knew, was that Yuni would have disapproved of such an obvious attack on those girls. Having them suddenly elope with a secret lover? Or marrying into another, less powerful family? Now those were the methods she was more likely to use. Having them die of some mysterious disease or a fatal food allergy after the fact would even ensure that the deaths couldn’t be linked back to her or Byakuran.)_

_It should have been exhausting, having a pair of violently over-possessive women hovering at either side of him all the time. But Tsuna found that things had become a whole lot easier to endure once he had them inserting themselves into his life._

_Byakuran and Yuni had managed to overturn nearly everything else he knew about himself. He supposed it only made sense that they managed to overturn his expectations in this, too._

**Author's Note:**

>  **TRIGGER WARNINGS:** The only one I can think of, in this piece, is Yuni's age. For starters, this is set when she's roughly fourteen or fifteen - which is still a bit skeevy when both Tsuna and Byakuran would be in their twenties, I agree. She _isn't_ in a physical relationship with either Tsuna or Byakuran, though they're all very interested in pursuing a more intimate relationship together at a later date. But Tsuna and Byakuran's behavior in this piece can be a potential trigger for anyone uncomfortable with underage sex or relationships - it's why I tagged this with Underage Character(s) at the top. Read at your own discretion.  
>  ***
> 
> In my defense, this started out with me writing a much longer oneshot. That one? Is still in the process of being finished. This was my brain hopping into the sin bin when I was _supposed_ to be working. Isn't that how it usually goes? Gah. *facepalms*
> 
> You have no idea how long I waffled back and forth over whether this was worth posting or not. 
> 
> I don't see too many people being interested in reading this, or even finding it good reading. But if you do, and if you had a bit of a laugh, consider leaving kudos and comments! I'd love to talk about how terrifying a fem!Byakuran is likely to be. Even if Tsuna _weren't_ completely besotted with her.


End file.
